Component composition of organic compounds of the assimilative apparatus of different species of the genus Aesculus affected by Cameraria ohridella (Lepidoptera, Gracillariidae)

Abstract

The most important disease for plants of the Aesculus genus is leaf spot caused by the leaf miner Cameraria ohridella (Lepidoptera , Gracillariidae) , which limits the use of Aesculus in landscaping in urban areas. The leaf miner C. ohridella is an insect widely spread in most European countries. The study was carried out in an urban area with six species of the genus Aesculus L. ( А e . hippocastanum L., A e . pavia L., A e . parviflora Walt., A e . flava Sol., A e . glabra Willd. and hybrid Aesculus × carnea ). The article reflects the results of research on the influence of the leaf miner C. ohridella on the peculiarities of changes in the chemical composition of chestnut leaf extracts. The component composition of the leaves of different ches t nut species was determined using chromatographic analysis. The study shows the results of the phytochemical screening of the leaves of different species from genus Aesculus , uninfested and infested with C. ohridella . A t otal of 186 chemical co m ponents were identified from the leaf extract s of Aesculus plants with six main groups of chemical components – carboh y drates, polyphenols, steroids, hydrocarbons, fatty acids and miscellaneous. The carbohydrates group is represented in the leaves of all studied Aesculus species in the maximum degree. The obtained data demonstrate significant change in the number of all chemical components under the influence of C. ohridella . The studied species showed an increase in carboh y drates content with the influence of leaf miner C. ohridella , except for such species as A e . flava and A e . parviflora . The qualitative composition of polyphenolic compounds was species-specific. The analysis of the composition of extracts of uninfested leaves established that four components were contained in extracts of Ae. hippocastanum and Ae. pavia , but they were different in their composition. In comparison with the composition of polyphenols in leaves without damage and leaves infected with C. ordidella , the absence of (2R-trans)-catechine in extracts from infected leaves of Ae. hippocastanum and Ae. glabra was found. U sing principal component analys i s , it was established that Ae. glabra shows a clear separation between chemical composition of the infested and uninfested samples. We identified two components of a phenolic nature only in extracts of infested leaves of Ae. flava , (trimethylsilyl catechollactate tris(trimethylsilyl) ether and epigallocatechin (6TMS)) , and quercetin was identified only in infected leaf extracts of Ae. glabra . Th ese results can indicate a greater pote n tial resistance of these Aesculus species to damage by the studied herbivory